1. Field
Embodiments of the present invention relates to a lamp unit to be used for a general projection-type display apparatus.
2. Description of the Related Art
As is well known, a projection-type liquid crystal TV, a liquid crystal projector, a DLP projector and other types of protection-type display apparatus require high luminance output in order to produce vivid picture images. Therefore, these types of display apparatus are normally implemented with lamp units capable of such high luminance output.
According to a light source unit (a lamp unit) to be used for such a projection-type display apparatus, in a lamp unit casing of a substantial box shape to store a light source lamp, a face (an output face) on which a light source is reflected on a reflector and is outputted is opened, and a rear face opposed to this output face is also opened (it is referred to as a rear opening face). In other words, the light source unit is shaped in a tubular shape, of which front and rear parts on an optical axis are opened.
In addition, a reflector and a front glass are held by a glass holder, and in an opening of the output face, a front part of this glass holder (a part where the front glass is fit) is engaged so that no air leaks from the front face. The light source lamp is incorporated in the reflector. According to such a lamp unit, an increase in luminance output causes an increase in the operating temperature of the light source lamp, so that cooling air is necessarily supplied to a heat generation portion from the outside.
In Jpn. Pat. Appln. KOKAI Publication No. 2002-365729, as a conventional art with respect to such a problem, the reflector of the lamp unit is positively cooled by an exhaust fan. In other words, providing an inflow hole and an outflow hole and using a fan, rising of a temperature of the reflector can be positively prevented.
In this Jpn. Pat. Appln. KOKAI Publication No. 2002-365729, only the rising temperature of the reflector is prevented. Such teachings do not address the regulation and control of rising temperatures on the light source lamp or the front glass on which filter processing is applied.